Precision of Single Precision Floats

There are two things wrong: (1) the value -8.32 can not be represented exactly in binary, and (2) SPIM prints out way too many digits.

Single precision floats have (recall) only 24 bits of precision. This is the equivalent of 7 to 8 decimal digits. SPIM prints out many more digits than are actually represented. This is incorrect. SPIM should have printed -8.319999 to the window.

The 7 or 8 decimal digits of precision is much worse than most electronic calculators. It is usually unwise to use single precision floating point in programs. (But these chapters use it since the goal is to explain concepts, not to write production grade programs). Double precision has 15 or 16 decimal places of precision.